Re: Analysis of redisplay performance on Windows

[Jason Rumney <jasonr@gnu.org>]

Chong Yidong wrote:
> Jason Rumney <jasonr@gnu.org> writes:
> 
>> As I suggested in my earlier email, new functions in the
>> font backend interface to select a font for working with and releasing
>> it when done, would help, as we could then skip doing this in
>> functions like encode_char and text_extents.
> 
> Could you suggest precisely what interface we need?  I.e., could you
> suggest function names and rough docstrings?

/* Optional.
   Begin using a font exclusively.
   Backends may setup the FONT for use on frame F here so that it
   does not need setting up in every call to the encode_char,
   text_metrics or draw functions.  The font remains current
   until done_font is called.  */
   functions.
void (*use_font) P_ ((FRAME_PTR f, struct font *font));

/* Optional.
   Finish using a font exclusively.
   Backends may undo the actions of use_font here.  */
void (*done_font) P_ ((FRAME_PTR f, struct font *font));